Identification of ortholog and paralog-specific amino acid evolution between the Drosophila sperm specific b2 tubulin, its major tubulin paralog beta-1 and its ortholog Glossina moristans beta-2 tubulin using molecular evolutionary genetics analysis (MEGA-X)
Kollin J. Clark
The Drosophila spermtail tubulin b2 is a highly conserved protein. Structure/function tests find that even small changes render b2 unable to generate motile sperm. A bioinformatic approach was used to identify evolving b2 amino acids as indicators of relaxed sites, by comparing b2 to closely related homologs. After aligning Dmb1 & Dmb2 and Gbm2 & Dmb2 sequences, the analysis found 13 positions that differed in amino acid polarity, charge, or acidity characteristics that would alter its interactions within the spermtail. There are seven sites between Dmb1 and Dmb2 paralogs that have different amino acids that also have different characteristics, and nineteen sites where Dmb1 and Dmb2 have different amino acids but similar characteristics. In ortholog comparisons, there are six sites where Gmb2 had different characteristics when compared to Dmb2 and twelve sites with different amino acids that have similar characteristics. There is some segregation between the b2 paralog and ortholog in terms of which sites are evolving, 2/6 (33%) of Gb2 characteristic change sites had overlap with Dmb1 and 2/7 (28.57%) of Dmb1 characteristic change sites had overlap with Gb2. This indicates the different functions of b1 and b2 have different amino acid requirements that impact which amino acids are capable of evolving.
Mark G. Nielsen
Primary Advisor's Department
Stander Symposium project, College of Arts and Sciences
"Identification of ortholog and paralog-specific amino acid evolution between the Drosophila sperm specific b2 tubulin, its major tubulin paralog beta-1 and its ortholog Glossina moristans beta-2 tubulin using molecular evolutionary genetics analysis (MEGA-X)" (2021). Stander Symposium Projects. 2095.